Production of olefin oxides and
carboxylic acids



3,346,473 PRODUCTION OF OLEFIN OXIDES AND CARBOXYLIC ACiDS Robert Stevenson Cofiey and Herbert George Lawley,

Norton-on-Tees, England, assignors to Imperial Chemical industries Limited, London, England, a corporation of Great Britain No Drawing. Continuation of application Ser. No. 180,016, Mar. 15, 1962. This application Dec. 28, 1964, Ser. No. 421,583 Claims priority, application Great Britain, Mar. 17, 1961, 9,812/ 61 11 Claims. (Cl. 204-158) This application is a continuation of our application Ser. No. 180,016, filed Mar. 15, 1962 and now abandoned.

This invention relates to the production of oxygen-containing organic compounds, particularly olefine oxides and organic acids.

According to the present invention, there is provided a process for the production of oxygen-containing organic compounds including olefine oxides and carboxylic acids which comprises the step of contacting a liquid mixture containing an aldehyde having two or more carbon atoms and an olefinic compound in which the double bond is in the terminal position and which contains three or more carbon atoms at a temperature in the range of 40 to 150 C. with a gas containing molecular oxygen.

A wide range of aldehydes may be used in the process of the present invention. Acetaldehyde is particularly suitable. Although higher straight-chain aliphatic aldehydes, for example propionaldehyde or n-buty-raldehyde, may be employed, these are less suitable because in their presence the occurrence of side reactions is increased and in consequence there is a decrease in the amount produced of carboxylic acid corresponding to the aldehyde and, to a lesser extent, a decrease in the amount produced of olefine oxide corresponding to the olefine. Branched chain aliphatic aldehydes, for example iso-butyraldehyde, may be used but they are less suitable than straight chain aldehydes because they are also more susceptible to side reactions. The use of a branched or unbranched higher aliphatic aldehyde, that is one containing three or more carbon atoms, leads in general to the formation of a mixture of acidic products comprising the expected carboxylic acid together with smaller amounts of carboxylic acids of lower molecular weight, and sometimes to a mixture of neutral products comprising lower aldehydes and ketones, all of these lower acids and neutral products resulting primarily from oxidative degradation of the aldehyde starting material. Although, in general, the use of lower aldehydes is preferable, it will be understood that the process may be carried out, although in an inferior manner, using higher aldehydes, and this mode of operation may sometimes be adopted, for example when a higher aldehyde is particularly readily accessible. The aldehyde to be used should also be selected to make the separation of products as easy as possible. For example, in the production of 1:2- epoxypropane by the co-oxidation of propylene, the use of aldehydes other than acetaldehyde may lead to difficulties in purification. Thus, if n-butyraldehyde is used in the process, the products obtained contain some propionaldehyde and acetone, and the separation of these from 1:2-epoxypropane may be difiicult. Aromatic aldehydes, such as benzaldehyde, are also suitable for use in the present process. Benzaldehyde has the advantage over aliphatic aldehydes having a similar number of carbon atoms that it is less liable to oxidative degradation.

A wide range of aliphatic mono-olefinic compounds in which the double bond is in the terminal position and which contain three or more carbon atoms is suitable for use in the process of the present invention. For example,

nited States Patent Ofiice Patented Oct. 10, 1967 it is possible to use propylene and higher straight-chain olefines containing up to fourteen carbon atoms and above. Thus, good results may be obtained using n-octene- 1. The presence of an alkyl group on the Z-carbon atom leads to a faster rate of production of the olefine oxide and a higher yield based on the aldehyde employed. Thus, although as disclosed above n-octene-l is suitable for use in the present process, even better results are obtained using Z-methylheptene-l.

It is also possible to employ olefinic compounds containing other functional groups such as, for instance, bydroxy, alkoxy, keto, carboxyl, ester, aryl and halide, in the process of the present invention. Thus, it is possible by the present process to convert allyl alcohol to a mixture of its oxide and one or more mono-esters of glycerol and these compounds are valuable intermediates in the production of glycerol. The use of di-olefines, such as butadiene, to give mono and/ or di-oxides, is also possible.

It is desirable to carry out the process of the present invention in the presence of an initiator which may be, for example, ultra-violet light; hydrogen peroxide; alkyl hydroperoxides and dialkyl peroxides having formulae R-OOH and ROO--R respectively, where R is an alkyl group such as tertiary butyl; diacyl peroxides such as diacetyl peroxide or cyclohexylsulphonyl acetyl peroxide; dialkyl peroxy dicarbonates such as di-isopropyl peroxy dicarbonate; peroxy esters such as tertiary butyl perbenzoate; and salts of metals of variable valency such as copper, manganese, nickel and cobalt. While inorganic salts may be employed, organic salts such as acetates, stearates, naphthenates, oleates, benzoates, acetonylacetates and acetoacetates are preferable because these are in general soluble under the reaction conditions employed and in consequence they are more eifective. Additionally, it is sometimes preferable to employ in conjunction a metal-containing initiator and an organic initiator, both being selected from the range of compounds listed above.

If desired, the present process may be carried out using a diluent, which is relatively inert to oxidation under the reaction conditions employed. Diluents which are particularly suitable are acetone, methyl acetate, ethyl acetate and acetic acid. It is possible to use other organic compounds, notably higher ketones, esters and carboxylic acids than those mentioned, but, in general, compounds containing methyl groups rather than CH or CH groups are preferable because they are less susceptible to oxidation. An exception ot this principle is that it is sometimes preferable to use as diluent the same carboxylic acid as that being produced in the process, even though this may contain -CH or CH groups. This is because the problem of separating the diluent from the acid produced does not then arise, and this advantage may outweigh partial degradation of the acid.

The process of the present invention is preferably carried out at a temperature of 60 to C. The reaction may be carried out at atmospheric pressure or at any suitable elevated pressure, the pressure being high enough to maintain the reaction mixture in the liquid phase and also to maintain a sufliciently high concentration of dissolved oxygen for the reaction to proceed at a convenient speed. The gas containing molecular oxygen may be oxygen itself, air, mixtures of nitrogen and oxygen, and oxygen together with any suitable diluent such as carbon dioxide or the olefine which is to be converted to its oxide. Thus, when propylene is to be oxidised, oxygen and propylene preferably in admixture with an inert diluent such as nitrogen may be fed together to the reaction zone; additionally, this mixture may also contain some propane, because it is generally more economic to use a propane-propylene mixture rather than propylene itself. As far as possible, the composition of gas mixtures used or produced in the present process should lie outside the explosive limits.

In general, it is desirable to operate at as high a molar ratio of olefine to aldehyde as is consistent with a satisfactory space-time yield. When operating batchwise, the total quantities of olefine and aldehyde to take part in the reaction are brought together and then a gas containing molecular oxygen is passed through the system. In this case, the molar ratio of olefine to aldehyde should be at least 5:1 and, if the olefine is a straight-chain, relatively involatile compound such as n-octene-l, the molar ratio should be 10:1 or greater. When using relatively volatile olefines, such as propylene, even higher ratios are desirable to off-set olefine carried over in the exit gas. In this latter case, good results are more likely to be obtained by using relatively high pressures and a relatively high oxygen concentration in the gas fed.

The reaction may also be carried out in a semi-continuous manner, that is the whole of the olefinic compound is fed initially and aldehyde is added continuously. In this case, good yields may be obtained with lower overall olefine:aldehyde molar ratios than those hitherto stated to be preferable. This is because, with the continuous addition of aldehyde, the stationary aldehyde concentration is low throughout and hence the olefinezaldehyde ratio at any one time is relatively high. For instance, a 70% yield of propylene oxide on aldehyde may be obtained using an overall propylenezaldehyde molar ratio of 8:1, and much lower molar ratios are suitable for less volatile olefines.

The reaction may also be carried out in a truly continuous manner, that is both olefine and aldehyde may be fed continuously to the reaction zone. The most suitable lefine2aldehyde molar ratio will then depend on the manner of operation. If the olefine and aldehyde are fed to the reactor separately but at closely adjacent points or as a combined stream at a single point it will be desirable for the molar ratio of olefinezaldehyde to be greater than :1 and preferably greater than 10:1. On the other hand, if the olefine is fed continuously into one end of the reactor and aldehyde is introduced continuously at a succession of points along the reactor, then a lower total olefinezaldehyde molar feed ratio may be employed. In general, lower olefinezaldehyde ratios may be used for olefines having a substituted rather than an unsubstituted 2-carbon atom.

It is desirable for the amount of molecular oxygen fed to be relatively great compared with the quantity of aldehyde employed. In this way, undesirable side reactions are decreased and the maximum space-time yield of desired compounds is obtained. In the continuous manner such as chelating agents, for instance ethylene diamine tetra-acetic acid and 8-hydroxy-quinoline, pyrophosphates and stannates to be incorporated in the reaction system.

The lower olefine oxides produced by the present process may be used, for example, in the production of polymers while the higher olefine oxides may be converted, for example, by hydrogenation, into alcohols, notably primary alcohols and these are suitable for use in the manufacture of plasticisers or detergents.

EXAMPLE 1 This example shows the advantage of having present an aldehyde during the oxidation of a hydrocarbon.

The method employed was to place the hydrocarbon in a glass flask having a volume of 500 mls., to raise this to the desired temperature and to pass gaseous oxygen through it at the rate of 15 litres per hour by means of a cruciform stirrer.

In an initial experiment, the oxidation of n-octene-l (0.5 mole; 56 grams) containing cobalt stearate (0.19 grams) was attempted. The reaction temperature was 7578 C. and operation was carried out for 140 minutes. At the end of this time, the reaction product was analyzed. It consisted almost entirely of unchanged noctene-l and it contained only 0002 equivalent of acid and 0.2 gram of olefine oxide.

The process was repeated except that during the first 135 minutes of reaction, n-butyraldehyde (0.25 mole; 18.0 grams) was added dropwise. The reaction product contained 0.185 equivalent of acid, this corresponding to 74% of theory, based on aldehyde employed. The reaction product was neutralised with sodium hydroxide, extracted with ether and the ethereal extract was fractionally distilled. In this way there were obtained unchanged aldehyde (0.3 grams), unchanged n-octene-l (39.7 grams),

1:2-epoxyoctane (14.8 grams) and other neutral oxidation products (10.0 grams), these consisting mainly of saturated ketones together with smaller amounts of alcohols and esters. The major acidic product obtained by acidification of the neutralised product was n-butyric acid, but traces of formic, acetic and proprionic acids Were present. The conversions of aldehyde and olefine were thus 98% and 29% respectively while the epoxide yield, based on reacted aldehyde and octene respectively was 47% and 79%. The ratio by weight of neutral liquid by-products to 1:2-epoxyoctane was 0.68:1.

EXAMPLE 2 Example 1 was repeated using n-butyraldehyde, the reaction being carried out at four different temperatures. The results are summarised in Table 1 below.

of operation, for example, at least two moles of oxygen should be fed per mole of aldehyde.

In carrying out the present process, the materials of construction of the apparatus are important. Thus, porcelain, enamel and resins are suitable for use. The metal sold under the registered trade mark Staybrite is particularly suitable and it is also possible to use surfaces of tin and aluminium. It is advantageous for the reaction vessel to have as great a volumezsurface area ratio as possible.

When, for example, the present process is carried out using an organic initiator, it is desirable for stabilizers This table shows that reaction temperatures of 34-100 C. are feasible, the best results being obtained at a temperature of 74 to 78 C.

EXAMPLE 3 (11.3 grams) and other liquid oxidation products (7.0 grams) were isolated. No unchanged aldehyde was detected. Thus, the conversions of aldehyde and olefine were 100% and 31% respectively, the yields of epoxide, based on reacted aldehyde and reacted olefine, were 35% and 93% and 21% respectively. The epoxide yields based on reacted aldehyde and reacted olefine were 29% and 66% respectively, while the acid yield based on reacted aldehyde was 63%. The weight ratio of neutral by-products 5 to epoxide was 0.58:1. 57% respectively and the Weight ratio neutral liquid by- On carrying out this experiment in the absense of added products to epoxide was 0.62: 1. n-butyraldehyde, the product was substantially unchanged EXAMPLE 4 n-octene-l containing less than 0.001 equivalent of acid and no epoxide. This example illustrates that the present process can be 10 EXAMPLE 7 carried out in a batchwise manner. The reaction was carried out as in Example 1 except that the n-butyraldehyde, This example shows that the reactor in which the presn-octene-l and cobalt stearate were all present initially ent process is carried out may be made of aluminium or at the beginning of the reaction. The crude reaction prodthe metal sold under the registered trademark Staybrite uct contained only 0.111 equivalent of acid. From the but that mild steel is unsatisfactory. crude product, unchanged aldehyde (0.9 gram), un- The reaction was carried out exactly as described in changed n-octene-l (42.2 grams), 1:2-epoxyoctane (9.7 Example 1 using n-butyraldehyde, 0.5 gram of filings of grams) and neutral liquid by-products (8.1 grams) were the metal under test being present in the reaction mixobtained. The conversions of aldehyde and olefine were ture. The results are given in Table II.

TABLE II Epoxide yield (percent) Neutral Dissolved metal in Aldehyde n-Octene-l Yield of acid liquid by Metal Tested reaction product conversion conversion (percent on products (ppm. by wt.) (percent) (percent) On On aldehyde (g. per g. aldehyde olefine reacted) epoxide) reacted reacted 96 37 3s 49 72 0.60 Aluminium i 98 34 37 53 73 0. s2 Stay-brite F 97 37 37 4s 70 0.56 Mild Steel 97 34 26 37 67 0. 70

This example illustrates the use of cyclohexylsulphonyl acetyl peroxide as initiator.

The process described in Example 1 using n-butyraldehyde was repeated except that cyclohexylsulphonyl acetyl peroxide (0.1 gram) was used instead of cobalt stearate, and that the passage of oxygen was continued for a further 30 minutes after the addition of the aldehyde had been completed. The crude product contained 0.072 equivalent of acid and from it unchanged n-octene-l (51.9 grams), unchanged aldehyde (4.0 grams), 1:2-epoxyoctane (4.8 grams) and other neutral liquid oxidation prod ucts (0.7 gram) were obtained. Thus, the conversions of aldehyde and n-octene-l were 78% and 7% respectively, while the yield of acid on aldehyde reacted was 37%. The yields of epoxide on reacted aldehyde and on reacted olefine were 19% and 98% respectively, and the weight ratio of other neutral by-products to epoxide was 0.15:1.

EXAMPLE 6 This example illustrates the use of ultra-violet light as an initiator.

The experiment described in Example 1 using n-butyraldehyde was repeated exactly as described except that no cobalt stearate was employed and that the reaction mixture was irradiated with a mercury vapour lamp. The crude reaction product contained 0.122 equivalent of acid, comprising mainly n-butyric acid together with traces of formic, acetic and propionic acids. On working up the crude reaction product, unchanged aldehyde (1.3 grams),

unchanged olefine (44.4 grams), 1:2-epoxyoctane (8.7

grams) and other neutral products (5.0 grams) were obtained. Thus, the conversions of aldehyde and olefine were Mild steel is clearly undesirable because it lowers the epoxide yield. gives a higher neutral liquid by-products epoxide ratio and gives a much higher metal content in the reaction product and is therefore relatively seriously corroded. Aluminium and the metal sold under the registered trademark Staybrite have no significant eifect on the reaction, but of the two the aluminium is dissolved to a greater extent.

EXAMPLE 8 This example illustrates operation under pressure using a diluted oxygen-containing gas.

An aluminium-lined pressure oxidation vessel was charged with a mixture of n-octene-l (560 grams; 5.0 moles), n-butyraldehyde (144 grams; 2.0 moles) and cobalt stearate (2.0 grams). The liquid was maintained at a temperature of 60-70 C. under a total pressure of 300 lbs. per square inch gauge. A gas consisting of 6% of oxygen and 94% of nitrogen by volume was passed at a rate of 850 litres per hour through the mixture for minutes. The crude reaction product contained 1.01 equivalent of acid. From the mixture, unchanged olefine (2.87 moles), unchanged aldehyde (0.24 mole), 1:2- epoxyoctane (0.28 mole) and neutral liquid by-products (95.4 grams) were isolated. Thus, the olefine and aldehyde conversions were 43% and 88% respectively. The epoxide yields based on reacted olefine and reacted aldehyde respectively were 13% and 16% while the yield of acid was 58%. The weight ratio of neutral liquid byproducts to epoxide was 2.65: 1.

Although an olefine oxide is produced by this mode of operation it will be noted that results are inferior to those obtained with a semi-continuous operation using undiluted oxygen.

EXAMPLE 9 This example illustrates the oxidation of a branchedchain aliphatic olefine in the present process.

In a blank experiment carried out under the conditions used in Example 1, an attempt was made to oxidise 224:4- trimethylpentene-l in the presence of cobalt stearate but in the absence of an aldehyde. The reaction product consisted essentially of unchanged hydrocarbon and contained only 0.0003 equivalent of acid and less than 0.2 gram of epoxide.

In a second experiment, n-butyraldehyde (0.25 mole; 18.0 grams) and 2:4:4-trimethylpentene-1 (0.5 mole; 56.0 grams) were oxidised as described in Example 1 in the presence of cobalt stearate (0.19 gram) at a temperature 8 EXAMPLE 12 This example shows that the co-oxidation of propylene and acetaldehyde is more satisfactory when carried out by a semi-continuous rather than the batchwise process of 78-80 C., the duration of the reaction being three as described in Exam 16s 10 and 11 Pf The Crude'PmdPct which contamed only 0055 An aluminium-lined reactor was charged with propylene equlvalent of acid, ylelded unchanged olefine (30.4 (758 grams; 1&0 moles), ethyl acetate (500 grams) and grams) unchanged aldehyde grams) lzlepoxy cobalt naphthenate (2.0 grams). This liquid was main- 2:4:4-tr1methylpentane (17.0 grams) and other products tained at a temperature of 650 and at a Pressure of (10'0 grams) Thus the Com/$101.15 of olefine and g 10 400 lbs. per square inch gauge for 95 minutes, during y were 46% and 86% respectlvely and the epoxlde which time acetaldehyde (88 grams; 2.0 moles) was inbased on reactad Olefine and reached aldehylie jected continuously. Simultaneously a gas stream containspectlvely, were 58% and 61%. The yleld or acid on in" by volume 8% of Oxygen and 92% by volume of l h reacted was and the Weight ratlo neutral ni t rogen was passed through at a rate of 735 litres per llquld by-products to epoxlde was 0.59:1. 15 hour, the gas flow being continued for ten minutes after EXAMPLE 10 the introduction of aldehyde was complete. From the product, acetaldehyde (0.48 mole), propylene oxide (1.09 h gi i g g 252 223 3: ig g iii gg igfi gg mole), acid (1.208 equivalent; essentially acetic acid), i fi 1d 5 lar rafo unchanged ethyl acetate diluent and higher-boiling oxida- 0 e e y h h 1 t t d b It tion products were recovered. The conversion of aldehyde Propy aceta e y at y 5 e co a was 76%, the yield of propylene oxide based on reacted naphthenate were charged to an aluminium-lined reactor a1 deb de was and the field of acid based on in the quantities given below in Table IIIA. actedigldehyde a 5 y TABLE 1114 In this example, the high yield of propylene oxide based h d E h 1 C b It 25 on reacted aldehyde should'be noted and compared with Run Propylene Acetfllde Y e Y 0 a the corresponding yield obtained by batchwise operation (mes) (mes) galls t lgifi sf in Example 10. Additionally, this method of aldehyde addition results in a low stationary aldehyde concentra- 9.29 5.45 575 2.0 tion and this in turn decreases the amounts of carbon 33% Z 3 3:3 monoxide and carbon dioxide formed as by-products.

EXAMPLE 13 The liquid was raised to a temperflture of 54-590 This example illustrates the co-oxidation of acetaldeat a Pressure 400 P Square mch i A hyde and n-octene-l. It also shows the advantage of using lure of 6% Oxygen and 94% by Volume mtmgen was 35 a diluent such as ethyl acetate or acetone rather than passed through at a rate of 850 litres per hour for fifteen operating in the absence of diluent minutes. In the three runs, the results given in Table (i) A mixture f acetaldehyde (11,0 grams; 0.25 mole) 11113 Obtalnedand n-octene-l (28.0 grams; 0.25 mole) was added dur- TABLE IIIB ing two hours to a mixture of n-octene-l (84.0 grams; 0.75 mole) and cobalt stearate (0.2 gram) contained in R filcgtalde fliglylieelig lgie l cig agi d Ngu gi q l gd a glass reactor and maintained at 7075 C. at atmos- N101} vel io n g dh (gereegt on aegtaldeh (gyp er p pherlc pressure. Gaseous oxygen was passed through at cent) a yd v d) py mode) a rate of 15 lltres per hour using a cruciform stirrer, the

converted) gas flow being continued for ten minutes after the alde- 4 36 12 7 hyde addition was complete. gg -3 41 431 (ii) A solution of acetaldehyde 0.25 mole) in ethyl 3 75 24 53 1.3 acetate (28.7 grams) was added as described in (i) above to a solution of cobalt stearate (0.2 gram) in n-octene-l This shows the advantages obtained in a batchwise (0.50 mole) and ethyl acetate (89.8 grams). The period process of using a high olefinezaldehyde molar ratio. of reaction, temperature and passage of oxygen were as escribed in paragraph (i). EXAMPLE 11 (iii) The experiment described in (ii) was repeated This example shows that the present process Can be except that the weights of acetone used for the acetaldeoperated in the absence of an initiator, provided that the hyde and n-octene-l solutions were 25,0 grams and 78.2 temperature is sufiiciently high. 55 grams respectively. Furthermore, the reaction temperature Propylene acetaldehyde moles) was only 56 C. and the duration of addition of the acetand ethyl ac tate (50 gra s) were Charged t0 an aldehyde solution was 100 minutes. The gas flow was aluminium-lined re ctor maintained at a temperature of continued for 210 minutes after acetaldehyde addition was 40 C. and at a pressure of 400 lbs. per square inch. A l t stream containing by volume 6% oxygen and 94% nitro- 60 The products were worked up in the usual manner and gen was passed through the solution at a rate of 850 r lt are given i T bl V b l litres per hour for 2.5 hours. This experiment was repeated at 55 C. and at 63 C., except that in these two TABLE V experiments the reaction time was only two hours. The results are given in the Table IV below. 65 gg gg 3 1E131? (gag g acia lagging;- TABLE v Experiment version (percent on acetaeetaldeproducts cent aldehyde hyde con- (g. per g.

converted) converted) olefine oxide) Propylene Yield of acid Neutral Acetaldehyde oxide yield (percent on liquid Temp.,C. conversion (percent on acetaldehyde by-products 57.3 17.5 46.0 1.47 (percent) acetaldehyde converted) (g. per g. pro- 95.5 32.4 66.4 0.51 converted) pylene oxide) 80.0 24.3 65.5 0.61

2% 2 2 These results clearly show the beneficial effect of the 76 2s 59 0.9 solvent on acetaldehyde conversion, yields of desired products and diminution of neutral liquid by-products.

9 EXAMPLE 14 In this example, the efficacy of various metal initiators is compared.

In all cases, acetaldehyde (0.25 mole) in ethyl acetate (25 mls.) was added over a period of 1 to 3 hours to a solution of the initiator to be tested (0.20 to 0.25 gram) in a mixture of n-octene-l (0.50 mole) and ethyl acetate (25 mls.). The temperature was maintained in the range of 5575 C., the pressure was atmospheric and gaseous oxygen was passed at a rate of 5 litres per hour through the solution during acetaldehyde addition and then for a period of 20 to 60 minutes. The products were analysed and the results are given in Table VI below.

10 EXAMPLE 17 This example shows the use of an olefine containing an aromatic grouping, namely styrene.

n-Butyraldehyde (0.25 mole; 18.0 grams) was added gradually during 90 minutes to a mixture of styrene (0.5 mole; 52 grams), ethyl acetate (72 grams) and cobalt stearate (0.2 gram) contained in a glass flask and maintained at a temperature of 7074 C. at atmospheric pressure. Gaseous oxygen was passed through at a rate of litres per hour, the flow of gas being maintained for a further 30 minutes after aldehyde addition was complete. The crude product, which contained 0.148 equivalent of acid, was worked up as described in Example 1. Un-

TABLE VI Neutral Epoxide Acid Reaction Aldehyde Acid Epoxide liquid byyield on yield on Initiator mp. conversion formed formed products acet alacetal- 0.) (percent) (equiv.) (mole) (g. per g. dehyde dehyde epoxide) converted converted (percent) (percent) Nil 55-74 6 0.012 0. 002 1. 0 13 80 Manganese naphthenate 68-72 68 0. 095 0. 034 0. 6 56 Copper naphthenate 68*74 72 0. 083 0. 043 1. l 24 46 Nickel stearate 68-75 72 0. 095 0. 043 0. 8 24 53 Vanadium naphthenate. 66-73 43 O. 041 0. 005 0. 7 5 38 Chromium stearate 67-71 36 0. 032 0. 010 1. 4 11 36 Ferric stearate 62-70 31 0. 029 0. 005 1. 8 6 37 These results show that manganese, copper and nickel are good initiators, while vanadium, chromium and iron are much less efficient.

EXAMPLE 15 This example illustrates the use of two organic initiators in the co-oxidation of n-octene-l and acetaldehyde. The procedure was as described in the previous example except that the initiators were dissolved in the aldehydeethyl acetate solution. The results obtained are summarised in the Table VII below.

EXAMPLE 18 This example shows the use of a di-olefine, namely butadiene.

TABLE VII Epoxide Acid yield Weight Reaction Aldehyde Acid Epoxide yield on on acetal- Initiator employed Temp. conversion formed formed acetaldehyde (gm.) 0.) (percent) (equiv.) (mole) dehyde converted converted (percent) (percent) Nil -74 6 0. 012 0. 002 13 80 Di-isopropyl peroxy dicarbonate 0.5 68-73 69 0. 046 0.033 19 27 Azo-bisisobutyronit e 5.0 63-71 34 0.057 0.021 25 67 EXAMPLE 16 This example shows the co-oxidation of acetaldehyde and isobutene.

A mixture of iso-butene (224 grams; 4.0 moles), ethyl acetate (440 grams) and cobalt naphthenate (2.0 grams) was charged to an aluminium-lined pressure vessel which was maintained at 80-85 C. under a total pressure of 400 lbs. per square inch gauge. Acetaldehyde (176 grams; 4.0 moles) was injected continuously over a period of 105 minutes and a stream containing by volume 10% oxygen and 90% nitrogen was passed through at a rate of 850 litres per hour. After the whole of the acetaldehyde had been added, the oxygen-nitrogen gas stream was continued for a further 15 minutes. Distillation of the reaction product gave unchanged iso-butene (1.74 moles), unchanged acetaldehyde (1.80 moles), iso-butene oxide (121.3 grams; 1.68 moles) and acetic acid (0.82 equivalent). The conversions of iso-butene and acetaldehyde were thus 56.5% and 55% respectively. The yields of isobutene oxide, based on reacted olefine and reacted aldehyde respectively, were 74% and 76%, while the yield of acid, based on aldehyde converted, was 37%.

Butadiene (3.97 moles), ethyl acetate (600 grams) and cobalt naphthenate (2.0 grams) were charged to an aluminium-lined reactor which was maintained at 73-76 C., at a pressure of 400 lbs. per square inch gauge for two hours, during which time n-butyraldehyde (2.0 moles) was introduced. During the whole of this time, a gas mixture containing by volume 8% oxygen and 92% nitrogen was passed through the liquid at a rate of 850 litres per hour. The flow of gas was maintained for 17 minutes after the addition of aldehyde was complete. The product contained 1.02 equivalent of acid, unchanged butadiene (1.9 moles), butadiene monoxide (0.97 mole), butadiene dioxide (0.17 mole), unchanged n-butyraldehyde (0.17 mole) and unidentified oxidation products. Thus, the conversions of butadiene and n-butyraldehyde were 52% and 91.5% respectively. The total molar yields of epoxide on aldehyde and on olefine converted were 71.5% and 55% respectively, while the molar yield of acid On aldehyde converted was 56%.

The process described above was repeated except that 4.0 moles of aldehyde were employed. The amounts of butadiene monoxide and butadiene dioxide isolated from the product were 0.80 mole and 0.52 mole respectively.

1 1 This indicates that the n-butyraldehyde:butadiene ratio affects the monoxidezdioxide ratio in the product.

EXAMPLE 19 This example shows the use of a branched-chain aldehyde.

n-Octene-l (0.5 mole) and iso-butyraldehyde (0.25 mole) were co-oxidised as described in Example 1, the reaction temperature being 65 C. and the duration of the reaction being two hours. The product contained 0.160 equivalent of acid, unchanged aldehyde (0.04 mole), unchanged n-octene-l (0.39 mole), 1:2-epoxyoctane (0.09 mole) and unidentified oxidation products. Thus, the conversions of n-octene-l and iso-butyraldehyde were 22% and 84% respectively. The epoxide yields on reacted olefine and aldehyde were 82% and 43% respectively, while the molar yield of acid on reacted aldehyde EXAMPLE 20 The process described in the previous example was repeated except that the aldehyde was 'benzaldehyde (0.25 mole) and the temperature was 90 C. The product contained unchanged n-octene-l (0.32 mole), 1:2 epoxyoctane (0.15 mole) and unidentified oxidation products. Thus, the n-octane-l conversions was 36%, while the epoxide yields on olefine reacted and aldehyde charged were 83% and 60% respectively.

We claim:

1. In a process for the production of olefine oxides and carboxylic acids the step of continuously contacting an aldehyde selected from the group consisting of acetaldehyde, propionaldehyde, n-butyraldehyde, iso-butyraldehyde and benzaldehyde with an olefinic compound selected from the group consisting of mono-olefines having from 3 to 14 carbon atoms in which the double bond is a terminal double bond, and butadiene, at a temperature in the range of 40 to 150 C. and in a liquid phase with a gas containing molecular oxygen, said olefinic compound being present in amounts greater than said aldehyde at any given time in the process.

2. A process as claimed in claim 1 in which there is employed at least one initiator selected from the group consisting of hydrogen peroxide; alkyl hydroperoxides having the formula RO-O-H where R is an alkyl group; dialkyl peroxides having the formula ROOR, where R is an alkyl group; diacyl peroxides; dialkyl peroxy dicarbonates, peroxy esters and ultra-violet light.

3. A process as claimed in claim 1 conducted in the presence of a diluent selected from the group consisting of acetic acid, methyl acetate, ethyl acetate and acetone.

4. A process as claimed in claim 1 in which there is employed as initiator a salt of a metal of variable valency selected from the group consisting of copper, manganese, nickel and cobalt.

5. A process as claimed in claim 1 in which the temperature of operation is 60 to 90 C.

6. A process as claimed in claim 1 in which the olefine is fed continuously in the proximity of one end of a reactor tube and the aldehyde is introduced continuously at a succession of points along said reactor tube.

7. A process as claimed in claim 1 in which the amount of oxygen employed exceeds, on a molar basis, the amount of aldehyde.

8. In a process for the production of propylene oxide and acetic acid the step of continuously contacting propylene with acetaldehyde in a liquid phase with a gas containing molecular oxygen at a temperature in the range of 40-150" C. and in the presence of a salt of a metal selected from the group consisting of copper, manganese, nickel and cobalt, said propylene being present in amounts greater than said acetaldehyde at any given time in the process and the amount of oxygen exceeding, on a molar basis, the amount of acetaldehyde.

9. A process as claimed in claim 8 in which the propylene is fed continuously in the proximity of one end of a reactor tube and the acetaldehyde is introduced continuously at a succession of points along said reactor tube.

10. In a process for the production of olefine oxides and carboxylic acids, the step of contacting an aldehyde selected from the group consisting of acetaldehyde, propionaldehyde, n-butyraldehyde, iso-butyraldehyde and benzaldehyde with an olefinic compound selected from the group consisting of mono-olefines having from 3 to 14 carbon atoms in which the double bond is a terminal double bond, and butadiene, at a temperature in the range of 40 to C. and in a liquid phase with a gas containing molecular oxygen, said process being carried out in a semi-continuous manner, the whole of the olefinic compound being fed initially and the aldehyde being added continuously and said olefinic compound being present in amounts greater than said aldehyde at any given time in the process.

11. A process for the production of an olefin oxide having at least three carbon atoms which comprises contacting a liquid mixture containing acetaldehyde and an olefin having at least three carbon atoms at a temperature of from 40-150 C. with a gas containing molecular oxygen in the presence of a catalyst selected from the group consisting of a salt of copper and cobalt.

References Cited UNITED STATES PATENTS 2,316,604 4/1943 Loder et al. 260-3485 2,567,930 9/1951 Findley et al. 260348.5 2,650,927 9/1953 Gasson et al. 260348.5 2,754,325 7/1956 Smith 260348.5 2,786,854 3/1957 Smith et al. 260348.5 2,833,813 5/1958 Wallace 260348.5 3,013,024 12/1961 Payne 260-3485 FOREIGN PATENTS 820,461 9/1959 Great Britain 260348.5

NORMA S. MILESTONE, Primary Examiner. 

1. IN A PROCESS FOR THE PRODUCTION OF OLEFINE OXIDES AND CARBOXYLIC ACIDS THE STEP OF CONTINUOUSLY CONTACTING AN ALDEHYDE SELECTED FROM THE GROUP CONSISTING OF ACETALDEHYDE, PROPIONALDEHYDE, N-BUTYRALDEHYDE, ISO-BUTYRALDEHYDE AND BENZALDEHYDE WITH AN OLEFINIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF MONO-OLEFINES HAVING FROM 3 TO 14 CARBON ATOMS IN WHICH THE DOUBLE BOND IS A TERMINAL DOUBLE BOND, AND BUTADIENE, AT A TEMPERATURE IN THE RANGE OF 40* TO 150*C. AND IN A LIQUID PHASE WITH A GAS CONTAINING MOLECULAR OXYGEN, SAID OLEFINIC COMPOUND BEING PRESENT IN AMOUNTS GREATER THAN SAID ALDEHYDE AT ANY GIVEN TIME IN THE PROCESS.
 2. A PROCESS AS CLAIMED IN CLAIM 1 IN WHICH THERE IS EMPLOYED AT LEAST ONE INITIATOR SELECTED FROM THE GROUP CONSISTING OF HYDROGEN PEROXIDE; ALKYL HYDROPEROXIDES HAVING THE FORMULA R-O-O-H WHERE R IS AN ALKYL GROUP; DIALKYL PEROXIDES HAVING THE FORMULA R-O-O-R, WHERE R IS AN ALKYL GROUP; DIACYL PEROXIDES; DIALKYL PEROXY DICARBONATES, PEROXY ESTERS AND ULTRA-VIOLET LIGHT.
 3. A PROCESS AS CLAIMED IN CLAIM 1 CONDUCTED IN THE PRESENCE OF A DILUENT SELECTED FROM THE GROUP CONSISTING OF ACETIC ACID, METHYL ACETATE, ETHYL ACETATE AND ACETONE. 